Subwoofer crossover (1 Viewer)

[Ryan T]

Hi,

I e-mailed Danny form GR-research about making the A/V 1's sealed and crossing them over at 100 Hz. Here is what he said.

" >my new sub is sealed and the mains will be crossed over 100 Hz so I won't be missing any bass form not having a port.<

I would not recommend this either. With the sub-woofer playing up that high it will be very directional. You will clearly hear sound emanating from the sub-woofer box. Placement in relation to the main speakers becomes critical. Phase and time delays can easily cause suck-outs or peaks in the response. Subs playing that high need to be placed really close to the speakers and a pair of them is really needed. Also if you are using any of our speakers don't put any high pass cross-overs in the signal path that will degrade the quality of the signal to the main speakers. This speakers are easily good enough to allow you to hear a clear difference in performance when you insert anything like a two-way sub-woofer crossover in the signal path. Just let the A/V-1's play wide open with nothing in the path. They will naturally begin to fall off at about 65Hz and be 3db down by 55Hz. After that they will fall at a 20db per octave rate. Then set your sub to cover the range from 50Hz on down. A 3rd order or 4th order electronic network on the sub will make blending them seamless. This will allow easy integration. Phase and time domain issues won't be issues. Placement will be a lot less critical, and overall sound will be much better."

I ruled out sealing the A/V 1's so now I just need to figure out the crossover part. Right now I'm powering my Tempest with a stereo receiver. So the only way to get a crossover at 50 Hz would be to

1. Buy a plate amp

2. Use a active car sub crossover I have laying around. Option number two would be better if it would work. considering I don't have the money for a good plate amp right now. I bought this Radio Shack crossover with 50, 90, 180 Hz crossover points a while ago but never really thought about it until Danny said a crossover at 50 Hz would be good. Will the Radio Shack crossover work well? if anyone has any ideas I'm open for suggestions, thanks.

Ryan

 

[jeff lam]

Ask Danny about the AV2.

If you want a sealed bookshelf these are it. He said these use a sealed design with his 6.5" driver. He said the 6.5" works best in a sealed enclosure and will act very similar to the 5.25" in a ported enclosure (AV1). They have nearly the same F3 as the AV1 and I would guess they would blend better with a sub. Ask him about it.

 

[Wayne A. Pflughaupt]

Ryan,

It would have been nice to get some details on your system instead of assuming everyone knows all about Danny, GR-research and what an AV-1 is. As such, much of the following is generic and may not be specifically applicable to your situation, but I’ll take a shot at it.

2. Use a active car sub crossover I have laying around. Option number two would be better if it would work considering I don't have the money for a good plate amp right now. I bought this Radio Shack crossover with 50, 90, 180 Hz crossover points a while ago but never really thought about it until Danny said a crossover at 50 Hz would be good. Will the Radio Shack crossover work well?

Once again, we have no specifics on the RS crossover. I expect it has shallow 12dB/octave slopes, which might be okay for a 90Hz high pass, but you can expect somewhat increased localization for the subs. If it has only 6dB/octave slopes, don’t bother.

Hope this helps.

Regards,

Wayne A. Pflughaupt

 

[Ryan T]

Oops I forgot to post the specs on the radio shack crossover. Here they are....

Power supply------------------ 14.4 V DC negative ground

Currnt Drain------------------ 30 mA

THD--------------------------- 0.04% at 20 Hz

Hum and noise----------------- 150mV typical

Line-level Input Impedance---- 10 kOhms

Speaker-level input impedance-- 100 Ohms

Operating voltage-------------- 10.5 to 16V DC

S/N ratio---------------------- 90 db (A-weighted)

Crossover frequency------------ 50 Hz/90 Hz/180 Hz

Crossover slope---------------- 12 db/Octave

Output level------------------- more than 2V RMS at 1% THD

Dimensions--------------------- 1x 3 9/16x 51/8 inches

weight------------------------- 10.2 oz

My current speakers are Paradigm Titans. I'm about to go build the GR-research A/V 1's. Having the speakers sealed is not that bug of a deal for me. My receiver is a Harman/Kardon AVR 120. The system is used for music 90% and HT 10%.

Since your speakers roll off at a relatively high 55Hz, I expect they are small speakers with small woofers? They would have to be pretty amazing to handle action flicks full-range, unless you have a really small room or don’t listen at high levels.

The A/V 1's are two-way speakers 1" dome tweeter and 5 1/4" woofer. I don't listen at very high levels and my room is very tiny (10' by 14'). The 100 Hz crossover I was referring to is my H/K crossover. I put the Radio Shack crossover in my system the set the Titans to large just to see what it sounds like. I set it at 50 Hz played some music. It did sound a little funny at first. But switching between the H/K crossover and the lower radio shack crossover I think I like it better at 50 Hz. I guess I just going to have to experiment with deferent crossover points when I get the A/V 1's built. Thanks for your help.

Ryan